1. Field of the Invention
The present invention relates to a high-pressure switching valve device for opening and closing a high-pressure fluid channel.
2. Description of the Related Art
FIG. 7 shows one example of a conventional high-pressure switching valve device.
In FIG. 7, reference symbol 1 denotes a high-pressure fluid channel, 1a denotes a high-pressure side of the high-pressure fluid channel 1, and 1b denotes a low-pressure side of the high-pressure fluid channel 1. The high-pressure fluid channel 1 is opened and closed by a high-pressure switching valve 2.
The high-pressure switching valve 2 consists of an electromagnetic solenoid valve. The electromagnetic solenoid valve 2 includes a coil 3, a fixed core 4 and the like on a fixed side and a plunger 5 on a movable side. A return spring 6 is provided between the fixed core 4 and the plunger 5. In the electromagnetic solenoid valve 2, if no current is applied to the coil 3, the plunger 5 is pressurized against the end face 8 of a valve seat 7 by the spring force of the return spring 6 to keep the high-pressure fluid channel 1 in a closed state. If a current is applied to the coil 3, a magnetic attraction force which attracts the plunger 5 toward the fixed core 4 is generated and this magnetic attraction force surpasses the spring force of the return spring 6, whereby the plunger 5 is separated from the valve seat end face 8 to open the high-pressure fluid channel 1.
As shown in an enlarged view of FIG. 8, the annular valve seat end face 8 is formed so that an inner peripheral section 8a protrudes upward of FIG. 8. When the valve 2 is closed, a seal member 9 consisting of the elastic member of the plunger 5 is pressed to contact with this inner peripheral or protruding section 8a, thereby exhibiting a sealing action. In addition, when the valve 2 is closed, the outer peripheral section 8b of the valve seat end face 8 is abutted on the outer peripheral section 10a of the end face of a valve main body 10 consisting of the high strength member of the plunger 5.